The best solution for my problem would be to install my wood furnace in the basement connected to the hvac system. No matter what I do to circulate air upstairs from the inserts it will not be warm enough for my wife and my basement is freezing without the gas furnace running. The gas furnace takes the chill off the air in the basement but not enough to heat it. My thought on the return vents was to close to upstairs and add 2 downstairs in the vertical riser using register grills with built in manual dampers so I can reverse them back in the summer for AC but I still don't think it will be enough. Currently the air coming out of the vents is in the low 70's with an ambient air temp of 78-80 degrees on the first floor upstairs bedrooms are 66-68 degrees.
Using hvac system to circulate woodstove heat?
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I am going to try something new on this that I think well work well. I am going to install a Honeywell vision pro thermostat on my main floor that can be connected to a wireless portable remote that i will place upstairs. the temp sensor to control the gas furnace can be controlled from either location or wireless temp sensor can be installed and they can be controlled from the remote. I want to try this and close vents on the main floor using the remote in the master bedroom at night and early morning while burning wood. Hopefully the warm air being pulled into the return and only trying to satisfy a thermostat in smaller area will result in less natural gas use.
My furnace air intake is at the top of a cathedral ceiling very close to the stove, so perfect situation if this method did work. I find running just the furnace fan doesn't make a noticeable heat difference, probably just barely warming the duct system while sending relatively cool air into the far rooms. So I've resigned myself just to burn some natural gas to bring the far rooms up to temp, while also pushing some of their cold air out.
I like the earlier post that stated furnace systems are expecting much hotter air coming out of the furnace into the exiting duct system.
I like the earlier post that stated furnace systems are expecting much hotter air coming out of the furnace into the exiting duct system.
I tried running the furnace on low speed constant and circulate mode which runs for 15-20 min then off for about the same highest air temp I seen at the vent up stairs was about 70 deg F checked with a fluke meter and thermocouple
I installed a Honeywell Prestige® IAQ thermostat wireless system last week. It has wifi capability and redlink (honeywell's bluetooth) with a wireless remote after a few days of use with one insert burning the combination works great. At night until early morning I switch to the remote located in the upstairs master bedroom and set it for 72 the first floor is usually around 78 at the stat in the hall. I close my first floor vents open all on the second floor and 2 in the basement. The furnace cycles a few times through the nigh and early morning but no where close to to just using the gas furnace the upstairs is very comfortable and the basement is warmer. Seems to work well so far plus I have wifi control and an outdoor temp sensor.
Imbalancing the system can cause the blower to race. This can lead to premature wear and burnout. Something to keep in mind.
I don't believe the system is imbalanced. The furnace has an ecm blower motor it runs at a very low speed and ramps up when the second stage of heating is needed I have never seen the furnace in the second stage. I do open 3 vents in the basement 1 rather large on the main truck that are normally closed when I close floor vents on the first floor all returns are left open. I have checked the blower motor several times it is turning slow there is not much pressure at the vents. The IAQ also has duct stats to monitor temperature and humidity it will send me an alert if it gets out of parameters.
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I just took current readings on the forced air furnace closing all vents on the first floor with fan only increased the current by 0.1 amps single stage heat also increased by 0.1 amps and second stage heat increased increased by 0.8 amps. Basement vents did not change the readings any. Max current was 3.5 amps with all 1st floor and and basement vents closed opposed to 2.7 with all vents open running in the second stage.
Thanks to all for the thoughts in this thread. This spring I installed a PE Super 27 in our house, which is kind of a side split....well, maybe more like a raised bungalow but with the ground level entry expanded into a living room and open up to the upper floor kitchen/dining room, with a vaulted ceiling in that whole area. The wood stove is in the living room, so the "middle floor" of the house. I was thinking and planning to add in a new air return to our existing forced air furnace, near the ceiling, to grab the hot air and distribute it through the house.
For now, I had been running a cheap pedestal fan on low, trying to push warm air down the upper floor hallway into the bedrooms, without having much success. I hadn't even started trying with the basement.
However, after reading through this thread I lowered that fan as much as I could to the floor and turned it around to pull the cold air from the hall/bedrooms into the living room. Amazing!! It totally changed the game and the bedrooms are significantly warmer! Tried it a bit today in the basement with the fan pushing up some cold air from the basement, and even there I'm noticing an improvement!
I had no idea to try something like this, so thanks again to all who suggested the idea of moving the cold air to the stove instead of the other way around!
For now, I had been running a cheap pedestal fan on low, trying to push warm air down the upper floor hallway into the bedrooms, without having much success. I hadn't even started trying with the basement.
However, after reading through this thread I lowered that fan as much as I could to the floor and turned it around to pull the cold air from the hall/bedrooms into the living room. Amazing!! It totally changed the game and the bedrooms are significantly warmer! Tried it a bit today in the basement with the fan pushing up some cold air from the basement, and even there I'm noticing an improvement!
I had no idea to try something like this, so thanks again to all who suggested the idea of moving the cold air to the stove instead of the other way around!
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That's the way to go. Early on we did a lot of experimenting and comparing notes here at H.com on different ways to move the heat. This was the conclusion I reached way back then and it's all I recommend now. It's easier to move denser cool air than warm air.
So then the question is: are there clever ways to accomplish this method in a more attractive way than having a fan sitting on one's floor all heating season? That's the appeal of using the HVAC system, since it's already all installed and tucked nicely out of the way.
In my case, I might be able to add a short run of out-of-sight ducting that pulls that cold air off the floor of the hallway and dumps it into the stove room right by the stove, using an inline duct booster fan.
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A ducted system may work, but usually, the heat losses defeat the gains. If this is a fully sealed and insulated ducted system within the heated envelope of the house, then maybe it will help. There's a lot more wiggle room in a furnace duct system designed to deal with 135º duct temps than 80º.
The dedicated, insulated duct run can work well if in a heated space. The fan can be on a cooling thermostat that turns on at a set room temp.
This is a necro-thread from 2020. But since it "tis" the season for stuff like this to come up, and I'm bored, why not?
I'll add my vote to moving cool air to the stove, not vice-versa. It seems to work better for whatever reason, and it's easier to have a fan on the floor anyway. Maybe it's because the floor is the part of the house that is unencumbered by obstructions. On average, doorways don't extend to the ceiling. I believe that energy loss in fan propelled air is going to be subject to the laws of affinity. Fan pushed air moving rapidly hitting an obstruction is going to lose energy at a square of its velocity, so much (4x) better to have the slower-moving return air working its way around the obstructions.
Once it comes to moving air around in ducts, I doubt it really matters as long as all things are made equal by having all the ducting within the insulated areas of the home. Physics kinda dictates that if you have X amount of air, and Y amount of heat, how you swish that around isn't going to change the total. If you move more of it to the colder part of your house, or more of it from the colder part of your house, you're not going to change the total, but the more you move, the warmer the outskirts of your house will be (and the cooler the center).
I think most of us heating with a wood forced air furnace are familiar with the concept. I know for me, the trick is to move as much relatively lukewarm air as possible to the outer edges of my house. During the winter, that means that my wood furnace blower runs 24/7 pumping air through flow-enhanced outlets at the outskirts. All central vents are closed. The returns are all located in the central parts, but despite the cold air moving through there, the central part of my house always feels a little warmer. I think this is because of the radiational effect - there are no cold outside walls/floors/ceilings to absorb heat, so the warm surrounds make it feel warmer. Of course, that's only necessary because most of us are using a HVAC duct system designed for an on-off traditional fuel furnace that has a much larger blower and a much warmer output. We've traded the house-wide on/off temp swings for the temp variations room-room. Pumping the only lukewarm air, only to the distant rooms, compensates for the larger heat loss there.
Back on topic: I think if you could move ALL of the air through the room that the heat source was in, using your HVAC to even out the temps would work (physics X, Y, yada, yada). But, if you're only moving a fraction of the air through that room, as any normal HVAC system would be designed to do, the results are going to be disappointing. They disappoint me. If I circulate mass quantities of air, by leaving it on all the time, it helps-some. This is offset by the cooling effect on humans by the air movement. If your ducts can lose heat to the outside, it could actually hurt. Having tried both, using floor fans at least moves all the air I'm actively trying to heat through the heat source room, and works better because the target room with the first fan in it gets the benefit, and usually the other rooms that I'm not motivated enough to put a fan in, are getting good enough natural circulation.
Real world, if you're trying to keep the plumbing in distant rooms from freezing, and all you have is a central wood stove and a HVAC system, turn the blower on. It'll help because the temp delta is high enough, and your plumbing doesn't feel drafts. I've been there. But, if you're trying to be comfortable, it probably won't help much, or it may make you less comfortable. Try it, but don't plan on it as a replacement for your existing HVAC heater.
I'll add my vote to moving cool air to the stove, not vice-versa. It seems to work better for whatever reason, and it's easier to have a fan on the floor anyway. Maybe it's because the floor is the part of the house that is unencumbered by obstructions. On average, doorways don't extend to the ceiling. I believe that energy loss in fan propelled air is going to be subject to the laws of affinity. Fan pushed air moving rapidly hitting an obstruction is going to lose energy at a square of its velocity, so much (4x) better to have the slower-moving return air working its way around the obstructions.
Once it comes to moving air around in ducts, I doubt it really matters as long as all things are made equal by having all the ducting within the insulated areas of the home. Physics kinda dictates that if you have X amount of air, and Y amount of heat, how you swish that around isn't going to change the total. If you move more of it to the colder part of your house, or more of it from the colder part of your house, you're not going to change the total, but the more you move, the warmer the outskirts of your house will be (and the cooler the center).
I think most of us heating with a wood forced air furnace are familiar with the concept. I know for me, the trick is to move as much relatively lukewarm air as possible to the outer edges of my house. During the winter, that means that my wood furnace blower runs 24/7 pumping air through flow-enhanced outlets at the outskirts. All central vents are closed. The returns are all located in the central parts, but despite the cold air moving through there, the central part of my house always feels a little warmer. I think this is because of the radiational effect - there are no cold outside walls/floors/ceilings to absorb heat, so the warm surrounds make it feel warmer. Of course, that's only necessary because most of us are using a HVAC duct system designed for an on-off traditional fuel furnace that has a much larger blower and a much warmer output. We've traded the house-wide on/off temp swings for the temp variations room-room. Pumping the only lukewarm air, only to the distant rooms, compensates for the larger heat loss there.
Back on topic: I think if you could move ALL of the air through the room that the heat source was in, using your HVAC to even out the temps would work (physics X, Y, yada, yada). But, if you're only moving a fraction of the air through that room, as any normal HVAC system would be designed to do, the results are going to be disappointing. They disappoint me. If I circulate mass quantities of air, by leaving it on all the time, it helps-some. This is offset by the cooling effect on humans by the air movement. If your ducts can lose heat to the outside, it could actually hurt. Having tried both, using floor fans at least moves all the air I'm actively trying to heat through the heat source room, and works better because the target room with the first fan in it gets the benefit, and usually the other rooms that I'm not motivated enough to put a fan in, are getting good enough natural circulation.
Real world, if you're trying to keep the plumbing in distant rooms from freezing, and all you have is a central wood stove and a HVAC system, turn the blower on. It'll help because the temp delta is high enough, and your plumbing doesn't feel drafts. I've been there. But, if you're trying to be comfortable, it probably won't help much, or it may make you less comfortable. Try it, but don't plan on it as a replacement for your existing HVAC heater.
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